Product Description:

The RAC 2.2-250-460-AP0-W1 is an AC main spindle drive controller produced by Bosch Rexroth Indramat for the RAC Spindle Drive Controllers series. Installed in machining centers and other automated tools, it converts command voltages from the CNC into regulated three-phase power that sets spindle torque and speed. By managing acceleration, constant-speed cutting, and deceleration, the unit helps maintain surface finish quality and tool life during production. This makes it suitable for spindle applications that require stable speed regulation during drilling, milling, and similar metal-cutting operations.

Thermal dissipation is handled by an integrated internal blower cooling system that pulls air through the heat sink without external ducting. The power stage supplies up to 250 A of continuous output current, supporting high-power induction or synchronous spindle motors. Input can be taken from 3 × AC 400 V, 50 Hz ±15% mains, and the same circuitry also accommodates 3 × AC 460 V grids used in North American plants. Speed reference arrives as a ±10 V analog speed command, allowing direct connection to conventional velocity-loop cards while preserving proportional response across the full speed range.

Field wiring terminates on the X4 9-pole interface, and rotor position is resolved with a high-resolution Indramat encoder that the controller samples for vector-control accuracy. A secondary channel accepts an additional encoder input so differential spindle feedback can be monitored when needed. This arrangement supports closed-loop spindle control when the machine requires both precise speed regulation and monitored rotor position. The unit is delivered without an additional bleeder, so external resistors are required where heavy regenerative braking is expected. The drive uses the series 2 design and is version 2.